---
name: "curl_unescape"
section: "3"
platform: "linux"
package: "curl"
version: "8.23.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/curl_unescape"
---

# curl\_unescape(3)

URL decode a string

## NAME

curl\_unescape - URL decode a string

## SYNOPSIS

```
#include <curl/curl.h>
char *curl_unescape(const char *input, int length);
```

## DESCRIPTION

Deprecated. Use *[curl\_easy\_unescape(3)](/curl_easy_unescape/3.md)* instead.

This function converts the URL encoded string **input** to a "plain string" and return that as a new allocated string. All input characters that are URL encoded (%XX where XX is a two-digit hexadecimal number) are converted to their plain text versions. Although not constrained by its type, the returned data may not be altered.

If the **length** argument is set to 0, *[curl\_unescape(3)](/curl_unescape/3.md)* calls strlen() on **input** to find out the size.

You must *[curl\_free(3)](/curl_free/3.md)* the returned string when you are done with it.

## PROTOCOLS

This functionality affects all supported protocols

## EXAMPLE

```
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    char *decoded = curl_unescape("%63%75%72%6c", 12);
    if(decoded) {
      /* do not assume printf() works on the decoded data */
      printf("Decoded: ");
      /* ... */
      curl_free(decoded);
    }
  }
}
```

## DEPRECATED

Since 7.15.4, *[curl\_easy\_unescape(3)](/curl_easy_unescape/3.md)* should be used. This function might be removed in a future release.

## AVAILABILITY

Added in curl 7.1

## RETURN VALUE

A pointer to a null-terminated string or NULL if it failed.

## SEE ALSO

**RFC**2396, [**curl\_easy\_escape**(3)](/curl_easy_escape/3.md), [**curl\_easy\_unescape**(3)](/curl_easy_unescape/3.md), [**curl\_free**(3)](/curl_free/3.md)